An examination of topics involved in statistical reasoning with imprecise probabilities. The book discusses assessment and elicitation, extensions, envelopes and decisions, the importance of imprecision, conditional previsions and coherent statistical models.

The Novum Organum, (or Novum Organum Scientiarum - "New Instrument of Science"), is a philosophical work by Francis Bacon, originally published in 1620. The title is a reference to Aristotle's work Organon, which was his treatise on logic and syllogism. In Novum Organum, Bacon details a new system of logic he believes to be superior to the old ways of syllogism. This is now known as the Baconian method.

Normative theories of obligation, moral and nonmoral value, and meta-ethical issues and theories are considered.

This article described three heuristics that are employed in making judgements under uncertainty: representativeness, which is usually employed when people are asked to judge the probability that an object or event A belongs to class or process B; availability of instances or scenarios, which is often employed when people are asked to assess the frequency of a class or the plausibility of a particular development; and adjustment from an anchor, which is usually employed in numerical prediction when a relevant value (...) is available. These heuristics are highly economical and usually effective, but they lead to systematic and predictable errors. A better understanding of these heuristics and of the biases to which they lead could improve judgements and decisions in situations of uncertainty. (shrink)

How can anyone be rational in a world where knowledge is limited, time is pressing, and deep thought is often an unattainable luxury? Traditional models of unbounded rationality and optimization in cognitive science, economics, and animal behavior have tended to view decision-makers as possessing supernatural powers of reason, limitless knowledge, and endless time. But understanding decisions in the real world requires a more psychologically plausible notion of bounded rationality. In Simple heuristics that make us smart (Gigerenzer et al. 1999), we (...) explore fast and frugal heuristics – simple rules in the mind's adaptive toolbox for making decisions with realistic mental resources. These heuristics can enable both living organisms and artificial systems to make smart choices quickly and with a minimum of information by exploiting the way that information is structured in particular environments. In this précis, we show how simple building blocks that control information search, stop search, and make decisions can be put together to form classes of heuristics, including: ignorance-based and one-reason decision making for choice, elimination models for categorization, and satisficing heuristics for sequential search. These simple heuristics perform comparably to more complex algorithms, particularly when generalizing to new data – that is, simplicity leads to robustness. We present evidence regarding when people use simple heuristics and describe the challenges to be addressed by this research program. Key Words: adaptive toolbox; bounded rationality; decision making; elimination models; environment structure; heuristics; ignorance-based reasoning; limited information search; robustness; satisficing; simplicity. (shrink)

This major work challenges some widely held positions in epistemology - those of Peirce and Popper on the one hand and those of Quine and Kuhn on the other.

According to the Harm Principle, roughly, the state may coerce a person only if it can thereby prevent harm to others. Clearly, this principle depends crucially on what we understand by harm. Thus, if any sort of negative effect on a person may count as a harm, the Harm Principle will fail to sufficiently protect individual liberty. Therefore, a more subtle concept of harm is needed. I consider various possible conceptions and argue that none gives rise to a plausible version (...) of the Harm Principle. Whether we focus on welfare, quantities of welfare or qualities of welfare, we do not arrive at a plausible version of this principle. Instead, the concept of harm may be moralized. I consider various ways this may be done as well as possible rationales for the resulting versions of the Harm Principle. Again, no plausible version of the principle turns up. I also consider the prospect of including the Harm Principle in a decision-procedure rather than in a criterion of rightness. Finally, in light of my negative appraisal, I briefly discuss why this principle has seemed so appealing to liberals. (shrink)

The author draws on the policy analysis literature to delineate the linkage between conceptualization of risk and the formulation and proposed solution of risk-related policy problems. Two concepts of risk are identified: a concept of risk as a physically given attribute of hazardous technologies and a concept of risk as a socially constructed attribute. The argument is advanced that the social construction of risk provides a firm, theoretical basis for the design of policy. The discussion links the perception, manage ment, (...) and communication of risk to the more fundamental issue of the nature and role of science and technology. (shrink)

We tested two consequences of a currently influential theory based on the notion of seeing adaptations to climate change as local adjustments to deal with changing conditions within the constraints of the broader economic–social–political arrangements. The notion leaves no explicit role for the strength of personal beliefs in climate change and adaptive capacity. The consequences were: adaptive action to climate change taken by an individual who is exposed to and sensitive to climate change is not influenced to a considerable degree (...) by their strength of belief in climate change and adaptive action to climate change taken by an individual who is exposed to and sensitive to climate change is not influenced to a considerable degree by their strength of belief in an adaptive capacity. Data from a 2004 questionnaire of 1950 Swedish private individual forest owners, who were assumed exposed to and sensitive to climate change, were used. Strength of belief in climate change and adaptive capacities were found to be crucial factors for explaining observed differences in adaptation among Swedish forest owners. (shrink)

Frank Ramsey was the greatest of the remarkable generation of Cambridge philosophers and logicians which included G. E. Moore, Bertrand Russell, Ludwig Wittgenstein and Maynard Keynes. Before his tragically early death in 1930 at the age of twenty-six, he had done seminal work in mathematics and economics as well as in logic and philosophy. This volume, with a new and extensive introduction by D. H. Mellor, contains all Ramsey's previously published writings on philosophy and the foundations of mathematics. The latter (...) gives the definitive form and defence of the reduction of mathematics to logic undertaken in Russell and Whitehead's Principia Mathematica; the former includes the most profound and original studies of universals, truth, meaning, probability, knowledge, law and causation, all of which are still constantly referred to, and still essential reading for all serious students of these subjects. (shrink)

This article rebuts Ramsey's earlier theory, in 'Universals of Law and of Fact', of how laws of nature differ from other true generalisations. It argues that our laws are rules we use in judging 'if I meet an F I shall regard it as a G'. This temporal asymmetry is derived from that of cause and effect and used to distinguish what's past as what we can know about without knowing our present intentions.

The following values have no corresponding Zotero field: PB - JSTOR.

The aim of this investigation is to answer the question of why it is prima facie morally wrong to cause or contribute to the extinction of species. The first potential answer investigated in the book is that other species are instrumentally valuable for human beings. The results of this part of the investigation are that many species are instrumentally valuable for human beings but that not all species are equally valuable in all cases. The instrumental values of different species also (...) have to compete with other human values. Sometimes these other values probably outweigh the value of the continued existence of the species. In general the degree of uncertainty is very high and the precautionaty principle is recommended to deal with these uncertainties. We also found that we have a duty to consider the interests of future generations of human beings and that these duties, in general, speak in favour of preservation. Anthropocentric instrumentalism therefore provides us with rather strong reasons to consider many cases of human caused extinction as prima facie morally wrong. Even so, anthropocentric instrumentalism does not fully account for the moral intuition we set out to investigate. The next potential answer that is investigated in the book is that species have a moral standing in their own right. The result of this part of the investigation is that this idea is highly unlikely, in particular because species cannot have any interests to consider. Anotgher potential answer is that species have intrinsic value in some other meaning that does not imply moral standing. We concluded that it is possible to be subjectively valued as an end and that many species have properties that make them highly suitable for being valued as ends by human beings. Finally, we found that our contributions to the extinction of species in most cases frustrate the interests of many non-human sentient beings. This is true if the species in question is made up of sentient individuals, and it is also true when the species in question is made up of non-sentient individuals that have instrumental value for sentient individuals of other species. There are exceptions to this rule, but all in all it seems that the inclusion of non-human sentient individuals together with us humans as moral objects, in most cases, tip the scale drastically in favour of preservation. The main result of the investigation is that there is not one but several explanations to why it is prima facie morally wrong to contribute to the extinction of species – and all of them are about duties to respect the interests of individual sentient animals, including human beings. (shrink)